What makes the link above great? It's a nice summary of medications commonly prescribed to treat "heart trouble" and high blood pressure. The concise descriptions (in language the layman can relate to) makes the expected actions of each medication quite easy to understand.
It is our individual responsibility to know what medications we are taking, the basics of why we take them, and how they work. It's our obligation to ask questions about our health and our medications if there is something we don't understand. (Your pharmacist will gladly take time to explain your medications and answer specific questions if you make it a point to ask.)
Here's a situation in which misunderstanding about medications caused serious consequences. Two women (we'll call them Susan and Mary) were having lunch together. Susan suffered from angina and felt the need to take a nitroglycerin pill for a "heart spell" she suffered during the luncheon, her symptoms were still causing discomfort after 5 minutes so she took another tablet (under her tongue) and then felt better. Mary was curious about this, because she also took a little white pill for her heart, but she had only been taking her pill once day. A few months later Mary felt her heart fluttering and suffered some chest discomfort. She remembered how Susan got relief from taking "extra doses" of her heart medication. Susan decided to take a few extra heart pills. Her symptoms didn't improve, and she was taken to the hospital. There she explained how she had tried to resolve the problem herself with the extra medications. When asked if she took nitroglycerin she replied, "I think so." But actually Mary was taking Digoxin--yes, it's a medication for the heart BUT it works quite differently. Mary suffered from a very low and irregular heart rate due to her Digoxin overdose--misunderstanding the basics about her medications nearly caused her death . . .